1. Field of the Invention
This invention relates to personal washing compositions which contain a cationic deposition polymer to increase deposition of a benefit agent onto the skin or hair.
2. The Related Art
For many years it has been known that hair can be conditioned by incorporation of silicone in a shampoo composition. U.S. Pat. No. 2,826,551 (Geen) is typical of an early disclosure of such 2 in 1 shampoos. Various attempts have been made to improve the efficiency of use of the expensive silicone component. This would provide better conditioning and the option of reducing the level of expensive benefit agent in the shampoo, with consequent cost saving.
Deposition polymers with a cationic charge have been proposed to enhance the amount of benefit agent deposited from the shampoo. For example cationic guar gum has been described for the enhancement of the deposition of antidandruff particles in U.S. Pat. No. 5,037,818 and for the enhanced deposition of insoluble non-volatile silicone in U.S. Pat. No. 5,085,857. The use of cationic polymers in shower gels to enhance deposition of silicone oil is also known from EP-A-457 688 (L'Oreal).
Deposition polymers have also been proposed to enhance the deposition of sunscreen materials from a shampoo composition. In EP 386 898 a cationic polygalactomannan gum derivative is used.
Polyacrylamides have been proposed for use in shampoos in EP 0 231 997. These polymers are not charged and do not assist in the deposition of benefit agents.
When washing with any of the prior art systems a considerable amount of the benefit agent will be rinsed away with the composition, and there is scope for substantially improving the deposition efficiency.
It is an object of the present invention to provide a more efficient deposition polymer than the previously described polygalactomannan polymers.